I have the 130 and the RTL510. My choice of the 130 was based upon my knowledge that I will never do power meter, heart rate monitor, cadence, or any other sensor-based stuff beyond the RTL (not that the 130 is incapable of these things). I don't care about color or touch screen and don't want or need routable maps. I just wanted a computer that could track my rides, had programmable screens, and could transfer my data to someplace else. For all that, the 130 was the right choice for me. In fact, it does a fair bit more than I was looking for.
sdmc530, I couldn't see small screens, either. I added
Hydrotac +2.50 stick-on bifocals to my riding glasses. Bazinga.